Putty knife



FIG. 1 is a perspective view of a putty knife in accordence with our new design;

FIG. 2 is a top elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a side elevational view thereof; and,

FIG. 6 is a bottom elevational view thereof. 

The ornamental design for a putty knife, as shown. 